ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Simultaneous production of cellulase and xylanase by Penicillium occitanis Pol6 and potential application in bioethanol production using cardboard waste as a sustainable substrate

Fatma Kallel, Semia Ellouz Chaabouni, and Mohamed Neifar

Laboratory for the Improvement of Plants and Valorization of Agroresources, National School of Engineering of Sfax (ENIS), University of Sfax, Sfax, Tunisia

E-mail: f111fatma@yahoo.fr

Received: 27 January 2025  Accepted: 5 May 2025

Abstract:

In Tunisia, paper and cardboard waste pose a significant environmental and energy burden. To address this, authorities are encouraging innovative biotechnological methods to transform these cellulose-rich wastes into valuable products like low-cost enzyme-inducing substrates. In this context, many industrialists are interested in co-producing multienzymes from a single potential microbe. Penicillium occitanis Pol6 was investigated for its potential to coproduce cellulase and xylanase in a cardboard waste-based medium. The simultaneous production of these two enzymes was optimized using response surface methodology (RSM) with a central composite design approach. The highest generation of cellulase (2.44 ± 0.07 U/mL) and xylanase (22.90 ± 3.84 U/mL) was reached with an initial cardboard waste (CW) concentration of 3 g/L and an inoculum size of 2%. The validation experiment confirmed the adequacy and accuracy of the proposed models. The enzymatic complex was used to hydrolyze CW, releasing 55 g L⁻¹ of reducing sugars after 24 h of saccharification of 120 g/L substrate. Fermentation of 4% of cardboard waste hydrolysates (CWH) with S. cerevisiae yielded a maximum bioethanol production of 15.5 g/L after 24 h of alcoholic fermentation. These results highlight the cost-effective potential of using CW as an inductive feedstock for simultaneous production of cellulase and xylanase by P. occitanis Pol6, offering significant benefits for both the economy and the environment.

Keywords: Biocatalysis; Biogas; Fungal biology; Fungi; Solid Biofuels; Polysaccharide sequencing; Penicillium occitanis Pol6; Cardboard waste; Response surface methodology; Cellulase; Xylanase; Bioethanol

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04119-z

Chemical Papers 79 (7) 4795–4805 (2025)